I recently updated the firmware on AXX6DRV3GEXP from v2.09 to v2.12. Before v2.12, the AXX6DRV3GEXP reported back to the Adaptec 3405 3Gb/s, now it reports 1.5Gb/s. I rolled back the firmware and did transfer rate tests using ATTO Disk Benchmark v2.41. Depending on the file size, you can see significant performance hits with 2.12 compared to 2.09. The current config is an Adaptec 3405, 4 Seagate 750's raid 10.